Mental health and well-being and chronic diseases like schizophrenia are health care issues of high priority to VA. Treatment of schizophrenia places a significant burden on the VA healthcare system. Veterans with schizophrenia occupy more hospital beds than veterans with any other illness1 and constitute at least 10% of homeless veterans receiving VA health care2. Although positive symptom reduction remains an important treatment goal, functioning in social and instrumental role domains is an important consumer and public health goal6. The President's New Freedom Commission on Mental Health report7 and the Comprehensive VHA Mental Health Strategic Plan4 emphasize the crucial importance of the Psychosocial Rehabilitation (PSR) approaches, targeting real world functioning outcomes. In order to develop and refine recovery-oriented treatment approaches, valid and sensitive measures of functioning in social and instrumental role domains are needed. As new treatments are tested, the need grows to demonstrate the real world gains by patients. Existing functioning measures are inadequate. We need a low cost, efficient, more objective measure, which is what Ecological Momentary Assessment (EMA) can provide. EMA is an ambulatory data collection technique that allows the real-time in vivo assessment of functioning behaviors, including social, educational, self- maintenance, daily activity, and employment activities. Modern EMA uses PDA microcomputer devices (EMAc) to signal participants several times throughout the day to respond to questionnaires about their recent activities. We propose to examine the convergence of EMAc assessments with real-world functioning ratings generated by patients and knowledgeable informants, performance-based measures of functional capacity, and neuropsychological test performance. This 3-year project will focus on pragmatic and psychometric questions that must be answered before EMAc can be used in clinical trials or in VA clinical settings. Specific Aim 1 (Construct Validity and Longitudinal Stability in a Simulated Clinical Trial): To examine test-retest reliability and construct validity of EMAc measures of real world functioning with regard to convergence between EMAc measures, standard ratings of real world functioning, neuropsychological test performance, performance-based functional capacity, and symptoms in 144 people with schizophrenia or schizoaffective disorder assessed at baseline and again at 4-week follow-up. We hypothesize that EMAc measures of real world functioning will be significantly correlated with standard ratings of real world functioning, neuropsychological test performance, and functional capacity test performance, and EMAc measures will lead to an improved fit compared to than standard self-report ratings of real world functioning in a confirmatory path model of the functional outcome construct that includes neurocognition, functional capacity, and symptom elements. Specific Aim 2 (Sensitivity to Impairment Relative to Healthy Individuals): To administer EMAc assessments to 100 healthy controls to examine sensitivity to patient-control differences and describe psychometric properties (e.g., test-retest reliability) of EMAc assessments in controls. We hypothesize that patients with schizophrenia or schizoaffective disorder will show significantly lower frequency of productive functioning behaviors on the EMAc functioning assessment total score relative to healthy individuals. EMAc is an innovative approach to measuring real world outcomes that takes advantage of advances in modern technology, software and ambulatory monitoring methodology. What EMAc would add to the study of functioning in people with mental disorders is simple and powerful: EMAc would provide an index of what people are actually doing in real-world settings. Accurate, efficient measurement of real world functioning is essential to the ultimate success of recent cognitive and PSR treatment and measurement efforts. The success of these efforts could ultimately lead to reduced disability in people with schizophrenia, which would have significant impact on patients and families, as well as broader societal and economic impact.